· Lie flat on a bench with your feet placed firmly on the floor and your abs drawn in. · Grasp the dumbbell in one hand and bring it up to the side of your chest, this is starting position. · Extend your arm, pressing the dumbbell up till your arm is straight and your elbow locked. · Using slow controlled movements, lower the weight to starting position. · Switch arms after completing reps with one arm. · Repeat.